Field of the Invention
The invention relates to an implement for applying a fluid, in particular, a stick-like writing or cosmetics implement. Such a prior art application implement, for example, is disclosed in German Patent DE 3910787 C1, the implement having a sleeve-like shank. A container for accommodating a fluid is disposed in the shank. Also provided is a fluid-directing system that, on one hand, bears a writing tip and, on the other hand, is in contact with the interior of the fluid container. The front end of the container is in fluidic connection with the atmosphere through an air-admission opening that is closed off by a semi-permeable diaphragm. As a result of which, air admission to, and air extraction from, the container is achieved with the writing tip retained in the upward direction. To ensure air admission and air extraction (for simplicity, reference is only made to air admission hereinbelow) in the case of an application implement with the writing tip retained in the downward direction, the prior art application implement has a transverse wall drawn into the container that includes, at least in part, a semi-permeable diaphragm that is impermeable to fluid and is permeable to air and water vapor. The transverse wall is joined, on the shank side, by a pressure-equalization chamber that is subdivided by a lip-valve-bearing transverse wall. Finally, an air-admission opening is provided in the shank-side or rear end wall of the container.
British Patent Document GB 715,043 discloses a ballpoint pen in which the fluid container is connected to the atmosphere by way of its rear end through a semi-permeable diaphragm. The diaphragm includes a non-porous elastic material, e.g., of latex, and allows the through-passage of air on account of molecular diffusion.
It is accordingly an object of the invention to provide an application implement that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that, with a straightforward construction, has a container that ensures constant pressure equalization with the atmosphere with the writing tip retained in the downward direction, that is to say during use, and with the writing tip retained in the upward direction as well as in the case of all other conceivable storage and use positions.
With the foregoing and other objects in view, there is provided, in accordance with the invention, an implement for applying a fluid, including a sleeve-like shank having a container, the container having an interior accommodating a fluid, a front end, a rear end, at least one of the front end and the rear end fluidically connected to the atmosphere for admitting air into and extracting air from the interior, and at least one air-admission opening connecting the interior to the atmosphere, a diaphragm permeable to air and impermeable to the fluid, the diaphragm closing off the air-admission opening, a writing tip of a capillary material, the tip connected to the shank, and a fluid-directing system fluidically connecting the writing tip to the fluid in the interior with the capillary material, the fluid-directing system directing fluid from the interior of the container to the writing tip. Preferably, the implement is a stick-like writing or cosmetics implement.
In accordance with another feature of the invention, the air-admission opening is disposed at the rear end of the container.
According to the application implement of the invention, there is disposed, at the rear end of the container, an air-admission opening that opens out directly into the fluid-containing container interior and is closed off by a semi-permeable diaphragm, i.e., one that is permeable to air and is impermeable to fluid. The construction makes it possible for the interior of the shank to be utilized to better effect and, thus, for a larger quantity of fluid to be stored. In the application implement disclosed from German Patent DE 3910787 C1, an air chamber is provided in the container, to the detriment of the quantity of fluid that can be stored. It has been found that the air admission in the writing position is possible even without an air-filled auxiliary chamber with lip valves disposed therein. The absence of such a construction feature simplifies the production of the application implement.
In accordance with a further feature of the invention, there is provided a second diaphragm permeable to air and impermeable to the fluid. The air-admission opening includes an air-admission opening at the front end, and the second diaphragm closes off the air-admission opening at the front end.
The air admission to the application implement with the writing tip retained in the upward direction preferably takes place through at least one air-admission opening that is disposed at the front end of the container and is likewise closed off by a semi-permeable diaphragm. The diaphragms are disposed, for example, adhesively bonded, on the outside or inside of the respective container wall having the air-admission opening. A configuration that further simplifies the production provides that the component having the air-admission opening is an injection molding with a diaphragm molded therein. It is, thus, possible for the container as a whole to be provided with the diaphragm during its production. As a result, there is no need for the diaphragm to be fixed subsequently on the container.
In accordance with an added feature of the invention, the container has a container wall with an inside surface and an outside surface, and the diaphragm and the second diaphragm are each disposed on one of the group consisting of the outside surface and the inside surface.
In accordance with an additional feature of the invention, the container is made by injection molding with the diaphragm molded therein.
In accordance with yet another feature of the invention, the container is made by injection molding with at least one of the diaphragm and the second diaphragm molded therein.
In a configuration that simplifies the production and the assembly, the fluid-directing system includes a tube with an essentially radially projecting flange that forms the front end wall of the container. The tube, the flange, and the container are preferably integral. As a result, on one hand, the assembly is facilitated and, on the other hand, leakages between the flange and container are avoided.
In accordance with yet a further feature of the invention, the fluid-directing system has a tube with a substantially radially projecting flange, and the flange forms a front end wall of the container.
In accordance with yet an added feature of the invention, the tube, the flange, and the container are integral and/or are formed in one piece.
In accordance with yet an additional feature of the invention, the circumferential wall of the container is formed by the shank itself, which reduces the number of parts and, thus, the assembly outlay.
In accordance with again another feature of the invention, the shank has a rear end and an outside, a stopper has an inside and closes off the rear end of the shank, and an air-admission channel fluidically communicating with the atmosphere is disposed between the inside of the stopper and the outside of the shank.
In accordance with again a further feature of the invention, a separate container is disposed in the shank. The air admission to the container through a diaphragm disposed at the rear end of the container is made possible in that an air channel that communicates with the diaphragm is provided between the outside of the sleeve and the inside of the shank.
In accordance with again an added feature of the invention, the container has an outer surface, the shank has an inner surface, the at least one air-admission opening is at least one rear air-admission opening, and an air channel is disposed between the outer surface of the container and the inner surface of the shank and fluidically communicates with the at least one rear air-admission opening.
In accordance with again an additional feature of the invention, the air channel opens out into a cavity that is connected to the atmosphere and is disposed between the tube of the fluid-directing system and an essentially sleeve-like tip part that encloses the fluid-directing system at a radial spacing therefrom. In the case of the separate container, an air-admission opening may be provided in the circumferential wall of the container. The configuration is associated, first of all, with the advantage that the air-admission opening may be of larger configuration than in the case of a configuration in an end wall of the container. In the case of the front end wall, in particular, the end-wall surface area available for air-admission openings is small because a bore has to be provided here through which the fluid-directing system can remove fluid from the container.
In accordance with still another feature of the invention, the air-admission opening in the circumferential wall of the container is at least one elongate air-admission opening extending from the front end of the container to the rear end of the container.
It is particularly advantageous if at least one elongate air-admission opening extends from the tip end of the container to the shank end of the latter. The configuration ensures air admission more or less in every position of the stick-like implement, particularly if a plurality of such elongate air-admission openings distributed over the container circumference is provided. It is possible to achieve the same effect as with the plurality of elongate air-admission openings if one air-admission opening extends helically over the container circumference. In such a case, as is also the case with the plurality of rectilinear elongate air-admission openings, air admission to the interior of the container is also possible in any desired rotary positionxe2x80x94in relation to the longitudinal axis of the application implement as axis of rotation.
In accordance with still a further feature of the invention, the container is an exchangeable cartridge.
In accordance with still an added feature of the invention, the cartridge has a front end wall defining a central opening, the fluid-directing system has a tube with a rear end, and the rear end of the tube is inserted releaseably into the central opening.
In accordance with still an additional feature of the invention, the fluid-directing system has a tube with an interior having an inner cross-section, the writing tip has a rear longitudinal section disposed in the tube, an insert is disposed in the interior of the tube and narrows the inner cross-section to form at least one longitudinally extending fluid channel in the interior of the tube, and the fluid channel adjoins the writing tip and fluidically communicates with the atmosphere for admitting air into and extracting air from the front end of the container.
In accordance with still another feature of the invention, the tube has an inner tube wall, the insert has a circumferential section abutting the inner tube wall, and at least one flattened portion disposed at a distance from the inner tube wall, and the inner tube wall and the flattened portion define the fluid channel.
In accordance with a concomitant feature of the invention, the fluid channel has a cross-sectional surface area decreasing in a direction of the container.
In a further inventive configuration, an insert that narrows the interior of the tube of the fluid device is disposed in the interior. The narrowing in cross-section makes it possible to produce axially running fluid channels that are considerably larger than the capillaries of a fibrous or sintered material and, thus, subject the fluid to a smaller capillary pressure. The high capillary pressure of the conventional materials involves the risk, in the case of application implements with free fluid stores, of fluid dripping out of the writing tip retained in the downward direction. Such a risk is prevented by the proposed configuration of the fluid-directing system. With the writing tip retained in the upward direction, it is possible to dissipate heating-induced pressure in the container through a fluid channel and an air channel provided between the writing tip and the inner wall of the tube. Conversely, air can penetrate into the container through the same route. It is, thus, possible to dispense with a diaphragm-closed air-admission opening in the front container region.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an application implement, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.